JP2000343391A - Pore polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an article having a through-hole consisting of a large-diameter portion and a small-diameter portion to be polished, in particular, a hole at the tip of a polished small-diameter portion in polishing a fine hole of a ferrule or a capillary for an optical connector. The present invention provides a pore polishing method capable of efficiently performing inner circumference polishing with high dimensional accuracy without causing roundness. SOLUTION: When polishing an article 1 having a through-hole 2 composed of a large diameter portion 3 and a small diameter portion 4 to be polished, a plurality of articles are placed in a cylindrical guide body 6 at positions on both ends thereof. In a state where the large-diameter portion is inserted and held so as to face outward, the polishing wire 5 is inserted into the through hole of each article, and lapping is performed. As the guide body, a guide cap having a through-hole formed of a large-diameter portion for fitting the small-diameter portion side end of the article to be polished and a small-diameter portion having an inner diameter equal to or slightly larger than the inner diameter of the small-diameter portion, It is also possible to use a guide body used in a state where the guide body is abutted against the small-diameter portion side end face of the article.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of polishing fine pores, and more particularly, to a dimension useful for finishing the inside diameter of an article having fine holes, particularly an article having an elongated through hole such as a ferrule or a capillary for an optical connector. The present invention relates to a highly accurate pore polishing technique.

[0002]

2. Description of the Related Art A ferrule or a capillary for an optical connector is a typical example having an elongated through hole and requiring high dimensional accuracy. Referring to the accompanying drawings, FIG. 7 shows a ferrule 10 in which an optical connector has a capillary portion 11 and a flange portion 12 which are integrated. That is, the ferrule 10
Is a capillary section 11 in which a small-diameter through hole 13 for inserting an optical fiber 17 (or an optical fiber) is formed along a central axis, and an optical fiber core 16 (of an optical fiber) along the central axis. With outer jacket attached to the outer periphery)
Flange part 12 in which large-diameter through hole 14 for insertion is formed
The small-diameter through-hole 13 and the large-diameter through-hole 14 are connected via a tapered diameter portion 15. The pair of optical fibers 17, 17 is connected by inserting the ferrules 10, 10 into which they are inserted and joined, from both ends of the split sleeve 18, and butting the ends of the ferrules 10, 10 together. The optical fibers 17, 17
The tip ends are butt-connected while the axes of are aligned.

FIG. 8 shows a capillary 1 of an optical connector.
1a and a flange 12a show a ferrule 10a for an optical connector which is a separate body. The hole diameter of the small-diameter through hole 13 for inserting an optical fiber varies depending on the type.
Φ0.12 for capillary (ferrule) called mold
It has pores of 6 mm and a depth of 10 mm.

In an optical connector, since it is required that the relative positions of two optical fibers to be connected are precisely adjusted, the outer diameter and the inner diameter of the ferrule or capillary (particularly, the inner diameter near the abutting surface) are required. High dimensional accuracy is required. Conventionally, ferrules or capillaries for optical connectors are molded by injection molding, extrusion molding, etc.
It is manufactured by subjecting a fired zirconia ceramic blank or the like to an inner peripheral polishing process, an outer peripheral polishing process, or the like. In addition, the present applicant has developed a method of manufacturing a ferrule or capillary for an optical connector made of an amorphous alloy (metallic glass) by a mold casting method, and has already applied for a patent. Metallic glass has excellent transferability on the surface of a mold, and has the advantage that ferrules or capillaries that do not require peripheral polishing or the like can be manufactured at low cost as long as the cavity surface of the mold has sufficient accuracy. However, at present, it is difficult to obtain sufficient dimensional accuracy for the small-diameter portion, so that the small-diameter portion requires fine-hole polishing as in the case of the ceramic-made portion.

[0005] The inner circumference polishing of the small diameter portion of the optical connector ferrule or capillary is generally performed by lapping. That is, as shown in FIG. 9, the polishing wire 5 is inserted into the through hole 2 of the blank 1 and stretched.
While supplying an abrasive such as diamond paste or polishing powder, the blank 1 is rotated by a blank gripping / rotating means (not shown), and the polishing wire 5 is reciprocated in the axial direction. Is polished (see, for example, JP-A-5-113523). At this time, as shown in an enlarged deformed manner in FIG. 10, the polishing wire 5 bends at the hole, so that the hole at the tip of the small-diameter portion 4 is polished into a curved surface and becomes rounded X. Japanese Patent Laid-Open No. Hei 6-118278 discloses that a plurality of ferrules are connected by sequentially fitting a plurality of ferrules into a rear recess of a front ferrule by inserting a front end protrusion of a rear ferrule. It has been proposed to simultaneously grind the inner circumference of the ferrule. However, also in this case, at the tip of the ferrule located at one end of the connecting body on the convex side, the hole at the tip of the small-diameter portion is polished into a curved surface due to the bending of the polishing wire, and becomes round.

The large-diameter portion 3 of the through hole 2 of the optical connector ferrule or capillary does not require such high dimensional accuracy, but the small-diameter portion 4 (especially near the distal end) requires high dimensional accuracy. If the hole at the tip of the small-diameter portion is rounded, the center position of the optical fiber to be inserted is shifted, which causes a problem that the optical fibers cannot be connected accurately. Therefore, conventionally, after polishing the fine holes, the tip of the small-diameter portion having a rounded hole opening is cut by grinding or the like, and C-face processing (chamfering) is performed, which increases the number of steps and reduces the yield. This contributes to an increase in manufacturing cost. Such a problem is not limited to a ferrule or a capillary for an optical connector, but is a problem common to fine hole polishing of an article having a through hole including a large diameter portion and a small diameter portion to be polished.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a polishing method for polishing a hole having a through hole having a large diameter portion and a small diameter portion to be polished. It is an object of the present invention to provide a pore polishing method capable of performing inner peripheral polishing with high dimensional accuracy without causing roundness. A more specific object of the present invention is to efficiently grind the inner periphery of a small-diameter portion with high dimensional accuracy, and therefore, there is no need to grind the front end portion of the small-diameter portion or C-surface processing as in the prior art. It is an object of the present invention to provide a method for polishing a ferrule or capillary for a connector.

[0008]

According to a first aspect of the present invention, there is provided a method for polishing an article having a through hole having a large diameter portion and a small diameter portion to be polished. Further, there is provided a pore polishing method characterized in that a polishing wire is inserted through through holes of a plurality of articles aligned and butt-matched so that a large diameter portion of the article is located at both ends, and lapping is performed. You.

According to a second aspect of the present invention, there is provided a method of polishing an article having a through-hole comprising a large-diameter portion and a small-diameter portion to be polished, wherein a plurality of articles are placed in a cylindrical guide body. A pore polishing method characterized by inserting a polishing wire into a through-hole of each article and performing lapping in a state where the large-diameter portions of the articles located at both ends are inserted and held so as to face outward. Is done.

According to a third aspect of the present invention, there is provided a method for polishing an article having a through hole comprising a large diameter portion and a small diameter portion to be polished, wherein the inner diameter is substantially the same as the outer diameter of the article. A small-diameter portion-side end of the article is fitted into a large-diameter portion of a guide cap having a through hole composed of at least one large-diameter portion and a small-diameter portion having an inner diameter equal to or slightly larger than the inner diameter of the small-diameter portion, A pore polishing method is provided, wherein a polishing wire is inserted into each through hole of the article and the guide cap and lapping is performed.

Further, according to a fourth aspect of the present invention, there is provided a method for polishing an article having a through-hole comprising a large-diameter portion and a small-diameter portion to be polished, the method comprising: In a state where the end face of the small-diameter portion side of the article is abutted against the end face of the guide body having a through hole having a slightly larger inner diameter, a polishing wire is inserted through each through hole of the article and the guide body, and lapping is performed. Is provided.

Any of the above methods can polish the pores with high dimensional accuracy, and can be advantageously applied particularly to the inner peripheral polishing of ferrules or capillaries for optical connectors having elongated through holes.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic idea of the pore polishing method of the present invention is to restrict the degree of freedom of the polishing wire at the tip of the small diameter portion where high dimensional accuracy is required so that no bending occurs. Accordingly, it is to prevent the hole at the tip of the small diameter portion from being rounded. For this purpose, the polishing wire is aligned so that the tip of the small-diameter portion is not located at a portion where the polishing wire is bent, or an appropriate guide member is provided at that portion. That is, a plurality of articles to be polished are always attached to the large-diameter portion side end and / or both ends where the polishing wire is bent.
Alternatively, the guide members are aligned so as to be positioned. As a result, the polishing wire does not bend at the tip of the small-diameter portion, so that the hole is not rounded. Even if the hole at the tip of the large-diameter portion is polished round as well as the guide body, there is no problem because the large-diameter portion is not required to have high inner diameter dimensional accuracy.

Even when a guide body is not used, the polishing wire can be aligned so that the large-diameter-side end is always located at both ends where the polishing wire is bent. For example, the small-diameter portions of a pair of articles to be polished are aligned so that the end faces thereof come into contact with each other, or are further joined with an appropriate binder, so that the large-diameter portions are always present at both ends. By simultaneously rotating a pair of articles to be polished in such a state and performing lapping, two pieces of inner circumference can be polished simultaneously, which is also efficient. In addition, a plurality of pairs of the articles to be polished in such a state can be similarly aligned and joined, whereby a large number of articles to be polished can be internally polished in a single step.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to the embodiments shown in the accompanying drawings. FIG. 1 shows an embodiment of the method of polishing a pore of the present invention, in which a blank 1 of a ferrule for an optical connector is used as an article to be polished and a cylindrical guide body 6 is used as a guide member. That is, a plurality of blanks 1 are inserted into a cylindrical guide body 6 having an inner diameter substantially the same as the outer diameter of the blank 1 so that the large diameter portions 3 are disposed outside the blanks 1 located at both ends. The polishing wire 5 is inserted into the through hole 2 of each blank 1. Pore polishing can be performed in the same manner as conventional lapping, that is, while supplying an abrasive,
This is performed by rotating the cylindrical guide body 6 (and each blank 1 held thereby) by a gripping / rotating means (not shown) and reciprocating the polishing wire in the axial direction. As shown in FIG. 1, the blank 1 accommodated in the intermediate portion (except for both side portions) of the cylindrical guide body 6 is stable so that the tip surfaces (PC contact surfaces) of the small-diameter portions 4 are in contact with each other. Although it is preferable that the large-diameter portion 3 and the small-diameter portion 4 are arranged at random positions, they can also be aligned.

As the cylindrical guide body 6, a pipe made of a material having a large coefficient of friction can be used. In addition, a split sleeve 6a in which a slit 7 is formed over the entire length in the longitudinal direction as shown in FIG. Plurality (preferably 3
A split sleeve 6b as shown in FIG. 3 in which the protrusions 8 are formed over the entire length in the longitudinal direction or intermittently can be suitably used. Such split sleeves 6a and 6b have the advantage that a plurality of blanks 1 can be elastically held, and in the case of the split sleeve 6b shown in FIG. 3 in particular, each blank 1 can be accurately positioned and held. can get. In addition,
In the case of the split sleeve 6b shown in FIG. 3, the cross section of each ridge 8 has a round cross-sectional shape such as a hemispherical shape as shown in the drawing or a substantially triangular shape with a rounded top end so as not to damage the blank 1. Should be.

FIG. 4 shows an embodiment of a fine hole polishing method using a guide cap 6c as a guide member. The guide cap 6c has a through hole including a large-diameter portion 9a having substantially the same inner diameter as the outer diameter of the blank 1 and a small-diameter portion 9b having an inner diameter equal to or slightly larger than the inner diameter of the small-diameter portion 4. The small-diameter portion 4 side end of the blank 1 is fitted into the large-diameter portion 9a of the guide cap 6c, and the blank 1 and the guide cap 6 are fitted.
The polishing wire 5 is inserted into each of the through holes 2, 9a, 9b of c, and lapping is performed. On the other hand, FIG. 5 shows an embodiment using a guide cap 6d having large-diameter portions 9a at both ends. In this case, the inner circumference of two blanks 1 can be polished in one polishing step.

FIG. 6 shows an embodiment using a cylindrical guide body 6e disposed on the end face side of the small diameter portion 4 of the blank 1 as a guide member. The guide body 6e has a through hole 9c having an inner diameter equal to or slightly larger than the inner diameter of the small diameter portion 4 of the blank 1. With the end face of the blank 1 on the side of the small diameter portion 4 abutting against the end face of the guide body 6e, the blank 1 and the guide body 6
The polishing wire 5 is inserted into each of the through holes 2 and 9c of e, and lapping is performed. The end face of the guide body 6e and the end face of the blank 1 on the side of the small-diameter portion 4 can be joined using an appropriate binder. In each of the above-described embodiments, the example in which the pore polishing method of the present invention is applied to a blank of an optical connector ferrule has been described, but the present invention is not limited to this, and the large diameter portion and the small diameter to be polished are described. It goes without saying that the present invention can be applied to all polishing of fine pores of an article having a through hole composed of a part.

[0019]

As described above, according to the pore polishing method of the present invention, in the polishing of the pores of an article having a through hole composed of a large diameter portion and a small diameter portion to be polished, the polished small diameter portion The inner periphery can be polished with high dimensional accuracy without causing roundness in the hole at the tip. Also, by applying the method of the present invention to the inner circumference polishing of a ferrule or a capillary for an optical connector, the inner circumference polishing of a small diameter portion can be efficiently performed with high dimensional accuracy. This eliminates the need for grinding and C-surface processing of the part, thereby improving productivity and reducing costs. Further, an advantage is obtained that an existing pore grinder can be used and no new capital investment is required. In addition, in the case of an optical connector ferrule or capillary precision-cast with metal glass, the outer periphery is not required to be polished, and the fine-polished one of the present invention can be used as a product as it is, so that the advantages of precision casting are utilized. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view for explaining one embodiment of a pore polishing method of the present invention.

FIG. 2 is a side view showing an embodiment of a cylindrical guide body.

FIG. 3 is a side view showing another embodiment of the cylindrical guide body.

FIG. 4 is a schematic sectional view for explaining another embodiment of the pore polishing method of the present invention.

FIG. 5 is a schematic sectional view for explaining still another embodiment of the pore polishing method of the present invention.

FIG. 6 is a schematic cross-sectional view for explaining another embodiment of the pore polishing method of the present invention.

FIG. 7 is a schematic partial sectional view showing a ferrule for an optical connector in which a capillary portion and a flange portion are integrated.

FIG. 8 is a schematic partial cross-sectional view showing a ferrule for an optical connector in which a capillary and a flange are separate types.

FIG. 9 is a schematic cross-sectional view illustrating a blank lapping process of a conventional ferrule for an optical connector.

FIG. 10 is an enlarged deformed view of a portion A in FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blank 2 Through-hole 3 Large diameter part 4 Small diameter part 5 Polishing wire 6 Cylindrical guide body 6a, 6b Split sleeve 6c, 6d Guide cap 6e Guide body 10, 10a Ferrule

Claims (5)

[Claims] 1. A method for polishing an article having a through-hole comprising a large-diameter portion and a small-diameter portion to be polished, the method comprising: A fine hole polishing method characterized by inserting a polishing wire through a through hole of an article and performing lapping. 2. A method for polishing an article having a through-hole comprising a large-diameter portion and a small-diameter portion to be polished, wherein a plurality of articles are placed in a cylindrical guide body at a large diameter of the article located at both ends thereof. The pore polishing method according to claim 1, wherein a polishing wire is inserted into a through hole of each article and lapping is performed in a state where the part is inserted and held so as to face outward. 3. A method of polishing an article having a through-hole comprising a large diameter portion and a small diameter portion to be polished, wherein the at least one large diameter portion having an inner diameter substantially equal to the outer diameter of the article and the small diameter portion are provided. The end of the small-diameter portion side of the article is fitted into the large-diameter portion of the guide cap having a through-hole formed of a small-diameter portion having an inner diameter equal to or slightly larger than the inner diameter of the article, and the through-hole of the article and the guide cap is polished. Polishing method, wherein a lapping process is performed by inserting a wire for use. 4. A method for polishing an article having a through-hole comprising a large-diameter portion and a small-diameter portion to be polished, wherein the guide body has a through-hole having an inner diameter equal to or slightly larger than the inner diameter of the small-diameter portion. A fine hole polishing method, wherein a polishing wire is inserted through each through hole of the article and the guide body in a state where the end face of the small diameter portion side of the article abuts against the end face, and lapping is performed. 5. The pore polishing method according to claim 1, wherein the article is a ferrule or a capillary for an optical connector.